logoalt Hacker News

human_llmtoday at 3:38 AM1 replyview on HN

I found it odd that they call it high-temperature, but then perform all their experiments at 4.2 K. Also, at 4.2 K, the magnet performs worse than established Nb-Ti technology, so it doesn't seem to be a significant advancement.


Replies

scythetoday at 3:45 AM

High-temperature superconductor refers to the critical temperature at zero field. But the crucial field decreases sharply with temperature, so the superconducting phase appears concave on a T–B phase diagram. Therefore, in order to operate superconducting magnets at high field, liquid helium is necessary irrespective of the superconducting transition temperature (critical temperature).